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| 1 | +/* |
| 2 | + LowPower_WithWorkAndGPIOInterrupt |
| 3 | + Adapted by Stephen Fordyce 2020-03-23 from: |
| 4 | + Artemis Low Power: How low can we go? |
| 5 | + By: Nathan Seidle |
| 6 | + SparkFun Electronics |
| 7 | + Date: February 26th, 2020 |
| 8 | + License: This code is public domain. |
| 9 | +*/ |
| 10 | + |
| 11 | +uint32_t msToSleep = 5000; //This is the user editable number of ms to sleep between RTC checks |
| 12 | +#define TIMER_FREQ 32768L //Counter/Timer 6 will use the 32kHz clock |
| 13 | +uint32_t sysTicksToSleep = msToSleep * TIMER_FREQ / 1000; |
| 14 | + |
| 15 | +const byte STATUS_LED = 14;//13 for Redboard onboard LED, 19 for Nano onboard LED |
| 16 | +const byte INPUT_BUTTON = 19;//You'll have to add one, it needs to connect to GND for active |
| 17 | + |
| 18 | +bool awakeFlag = true; //Stops wakeFromSleep() being run if the system is already awake |
| 19 | + |
| 20 | + |
| 21 | +// GPIO Interrupt Service Routine |
| 22 | +void myGPIO_ISR(void) |
| 23 | +{ |
| 24 | + detachInterrupt(digitalPinToInterrupt(INPUT_BUTTON)); //Stop interrupt from being triggered again |
| 25 | + wakeFromSleep(); //Without waking the processor properly, nothing more will happen. This means wakeFromSleep() is called twice though. |
| 26 | +// am_hal_stimer_compare_delta_set(6, 0); //Or, force the timer to run out, and resume from where you left off. |
| 27 | +} |
| 28 | + |
| 29 | + |
| 30 | +void setup(void) { |
| 31 | + Serial.begin(115200); |
| 32 | + Serial.println("Artemis Low Power (with timer & GPIO wakeup) Example"); |
| 33 | + pinMode(STATUS_LED, OUTPUT); |
| 34 | + pinMode(INPUT_BUTTON, INPUT_PULLUP); |
| 35 | + //Initialise stuff like I2C/Wire/SPI here |
| 36 | +} |
| 37 | + |
| 38 | + |
| 39 | +void loop(void) { |
| 40 | + Serial.println("Starting loop, and flashing LED"); |
| 41 | + digitalWrite(STATUS_LED, HIGH); |
| 42 | + delay(200); |
| 43 | + digitalWrite(STATUS_LED, LOW); |
| 44 | + Serial.println("Phew, that was hard work, sleep for 4 seconds"); |
| 45 | + msToSleep = 4000; |
| 46 | + sysTicksToSleep = msToSleep * TIMER_FREQ / 1000; |
| 47 | + goToSleep(); |
| 48 | +} |
| 49 | + |
| 50 | + |
| 51 | +//Power everything down and wait for interrupt wakeup |
| 52 | +void goToSleep() |
| 53 | +{ |
| 54 | + attachInterrupt(digitalPinToInterrupt(INPUT_BUTTON), myGPIO_ISR, FALLING); |
| 55 | + |
| 56 | + //End stuff like I2C/Wire/SPI here |
| 57 | + |
| 58 | + power_adc_disable(); //Power down ADC. It it started by default before setup(). |
| 59 | + |
| 60 | + Serial.println("Going to sleep"); |
| 61 | + delay(50); //Wait for serial to finish |
| 62 | + Serial.end(); //Power down UART(s) |
| 63 | + awakeFlag = false; |
| 64 | + |
| 65 | + //Disable all pads except the interrupt button |
| 66 | + for (int x = 0 ; x < 50 ; x++) |
| 67 | + { |
| 68 | + if(x != INPUT_BUTTON) |
| 69 | + am_hal_gpio_pinconfig(x , g_AM_HAL_GPIO_DISABLE); |
| 70 | + } |
| 71 | + |
| 72 | + //We use counter/timer 6 to cause us to wake up from sleep but 0 to 7 are available |
| 73 | + //CT 7 is used for Software Serial. All CTs are used for Servo. |
| 74 | + am_hal_stimer_int_clear(AM_HAL_STIMER_INT_COMPAREG); //Clear CT6 |
| 75 | + am_hal_stimer_int_enable(AM_HAL_STIMER_INT_COMPAREG); //Enable C/T G=6 |
| 76 | + |
| 77 | + //Use the lower power 32kHz clock. Use it to run CT6 as well. |
| 78 | + am_hal_stimer_config(AM_HAL_STIMER_CFG_CLEAR | AM_HAL_STIMER_CFG_FREEZE); |
| 79 | + am_hal_stimer_config(AM_HAL_STIMER_XTAL_32KHZ | AM_HAL_STIMER_CFG_COMPARE_G_ENABLE); |
| 80 | + |
| 81 | + //Setup interrupt to trigger when the number of ms have elapsed |
| 82 | + am_hal_stimer_compare_delta_set(6, sysTicksToSleep); |
| 83 | + |
| 84 | + //Power down Flash, SRAM, cache |
| 85 | + am_hal_pwrctrl_memory_deepsleep_powerdown(AM_HAL_PWRCTRL_MEM_CACHE); //Turn off CACHE |
| 86 | + am_hal_pwrctrl_memory_deepsleep_powerdown(AM_HAL_PWRCTRL_MEM_FLASH_512K); //Turn off everything but lower 512k |
| 87 | + am_hal_pwrctrl_memory_deepsleep_powerdown(AM_HAL_PWRCTRL_MEM_SRAM_64K_DTCM); //Turn off everything but lower 64k |
| 88 | + //am_hal_pwrctrl_memory_deepsleep_powerdown(AM_HAL_PWRCTRL_MEM_ALL); //Turn off all memory (doesn't recover) |
| 89 | + |
| 90 | + // Enable interrupts to the core. |
| 91 | + am_hal_interrupt_master_enable(); |
| 92 | + |
| 93 | + //Enable the timer interrupt in the NVIC. |
| 94 | + NVIC_EnableIRQ(STIMER_CMPR6_IRQn); |
| 95 | + |
| 96 | + //Go to Deep Sleep. |
| 97 | + am_hal_sysctrl_sleep(AM_HAL_SYSCTRL_SLEEP_DEEP); |
| 98 | + |
| 99 | + ///////////////////////////////////////////////////////////////////// |
| 100 | + //<Pause here while sleeping> (and/or while interrupt routines run)// |
| 101 | + ///////////////////////////////////////////////////////////////////// |
| 102 | + |
| 103 | + //Turn off timer interrupt |
| 104 | + NVIC_DisableIRQ(STIMER_CMPR6_IRQn); |
| 105 | + |
| 106 | + //Turn off GPIO interrupt |
| 107 | + detachInterrupt(digitalPinToInterrupt(INPUT_BUTTON)); |
| 108 | + |
| 109 | + //We're BACK! |
| 110 | + wakeFromSleep(); |
| 111 | + Serial.println("End of goToSleep()"); |
| 112 | + Serial.println(); |
| 113 | +} |
| 114 | + |
| 115 | + |
| 116 | +//Power everything up gracefully |
| 117 | +void wakeFromSleep() |
| 118 | +{ |
| 119 | + if(awakeFlag) //Already awake |
| 120 | + return; |
| 121 | + |
| 122 | + //Power up SRAM, turn on entire Flash |
| 123 | + am_hal_pwrctrl_memory_deepsleep_powerdown(AM_HAL_PWRCTRL_MEM_MAX); |
| 124 | + |
| 125 | + //Go back to using the main clock |
| 126 | + am_hal_stimer_int_enable(AM_HAL_STIMER_INT_OVERFLOW); |
| 127 | + NVIC_EnableIRQ(STIMER_IRQn); |
| 128 | + am_hal_stimer_config(AM_HAL_STIMER_CFG_CLEAR | AM_HAL_STIMER_CFG_FREEZE); |
| 129 | + am_hal_stimer_config(AM_HAL_STIMER_HFRC_3MHZ); |
| 130 | + |
| 131 | + //Turn on ADC |
| 132 | + ap3_adc_setup(); |
| 133 | + |
| 134 | + //Set any pinModes |
| 135 | + pinMode(STATUS_LED, OUTPUT); |
| 136 | + pinMode(INPUT_BUTTON, INPUT_PULLUP); |
| 137 | + |
| 138 | + //Optional - start again (will never reach the end of goToSleep() or wakeFromSleep() though) |
| 139 | + //Note - global variables will be preserved if you don't power down SRAM (comment out the line) |
| 140 | +//setup(); |
| 141 | + |
| 142 | + //Restart Serial |
| 143 | + Serial.begin(115200); |
| 144 | + delay(10); |
| 145 | + Serial.println("Back on"); |
| 146 | + awakeFlag = true; |
| 147 | + |
| 148 | + //Initialise stuff like I2C/Wire/SPI here |
| 149 | +} |
| 150 | + |
| 151 | + |
| 152 | +//Called once number of milliseconds has passed |
| 153 | +extern "C" void am_stimer_cmpr6_isr(void) |
| 154 | +{ |
| 155 | + uint32_t ui32Status = am_hal_stimer_int_status_get(false); |
| 156 | + if (ui32Status & AM_HAL_STIMER_INT_COMPAREG) |
| 157 | + { |
| 158 | + am_hal_stimer_int_clear(AM_HAL_STIMER_INT_COMPAREG); |
| 159 | + } |
| 160 | +} |
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